1. Field of the Invention
This invention relates, in general, to industrial filter systems and, more particularly, to an industrial filter system and substance delivery method that is adapted for use in delivering a fine, dry powder such as cement, barite, hematite, fly ash or the like into an open pit or vessel in a manner substantially reducing the amount of dust normally created by such operations.
2. Description of the Related Art
Various industrial applications require the introduction or transportation of a fine dry powder such as cement, barite, hematite, fly ash, kiln dust or the like into an open pit or receptacle. For example, in the oil industry, sludge pits created in oil fields must be "cleaned-up" or remediated. This is usually accomplished by dewatering the sludge pit and then adding a solid powder material such as fly ash to the sludge pit to solidify the sludge for removal or further treatment. Conventionally, the powder material is pneumatically conveyed from a pressurized storage tank or closed tank truck directly into the sludge pit. The pneumatic tank truck is typically equipped with a blower which creates a higher than atmospheric pressure inside the delivery tank which causes the powder substance to flow from the tank to the desired area in a stream of air. The powder substance is entrained in the air stream. As the substance is conveyed to the open pit with such a stream of air, the substance is released into the pit with such air causing a substantial amount of dust and particulate matter to be released into the atmosphere thereby polluting the surrounding environment. As is understood, such a process creates an unsafe and unhealthy work environment for those involved in the process. Similar problems are created whenever a powder substance is transferred in a stream of air to an open receptacle or vessel in other industrial applications.
Various filter systems are known to filter powder substances. One of the most common devices incorporates a fan dust collector. Such a collector is very expensive, both to build and to maintain, and is typically stationary so it can be used only at a particular location. Thus, the use of such device is particularly disadvantageous, and inapplicable, to situations involving transporting or delivering powder substances to open pits at remote locations.
Portable industrial filters are also known in the art such as that disclosed in U.S. Pat. No. 4,844,665 issued to Howell on Jul. 4, 1989. The Howell patent discloses a filter system for use in filtering a vented air stream from a closed container after the air stream has delivered a substance to such closed container where the vented air stream may carry over some dust or particulate matter. Howell does not disclose a method of transferring a powder substance directly to an open receptacle in a manner substantially reducing the amount of dust created in the surrounding atmosphere.
Thus, a need exists for a portable filter system that is adapted for use in transporting or delivering a powder substance to an open air receptacle in a manner significantly reducing the amount of particulate pollution or dust typically accompanying such an operation.